Pharmacologically active j,b-diaza-
bicyclo-[j,z,l]-octanes



United States Patent 3,281,421 PHARMACOLOGICALLY ACTIVE 3,8-DIAZA- BICYCLO-[3,2,1]-0CTANES Giorgio Cignarella, Milan, Italy, and Emilio Testa, Tessin, Switzerland, assignors t0 Lepetit S.p.A., Milan, Italy N0 Drawing. Filed June 18, 1962, Ser. No. 202,994 Claims priority, application Great Britain, June 26, 1961, 23,07 6/ 61 Claims. (Cl. 260-268) The present invention relates to new pharmacologically active compounds. More particularly this invention is concerned with new 3,8-diazabicyclo-[3,2,1]-0ctanes of the formula:

rat intestine at a concentration of 0.030.05'y/ml., said activity of the racemic form of the compound in question is primarily due to the levo form, which produces the same effect at a concentration of 0.01-0.03 'y/ml.

3-methyl-8-propionyl 3,8-diazabicyclo-[3,2,ll-octane was found to be highly active as an analgesic. In experiments carried out on rats according to Randall and Selittos method, when administered by intraperitoneal route it caused a percentage increase of the pain threshold to the pressure stimulus of 42 at the dose of 7.5 ing/kg. and of 139 at the dose of 10 mg./kg.

The same activity is observed after oral administration. The intraperitoneal administration of 10 mg./kg. to mice causes a variation of the reaction time to the pain stimulus due to a hot plate according to Eddys method, as determined 20 minutes after giving the drug of +2.5 seconds, while a variation of +4.36 seconds is observed with 25 mg./kg. Orally the variation is +2.30 seconds at 10 mg./kg. and +4.89 at 25 mg./kg.

The compound 3-cinnamy1-8-propionyl-3,S-diazabicyclo-[3,2,1]-octane is also exceptionally active as an analgesic. The percentage increase in pain threshold in rats is intraperitoneally 46.5, 75.8 and 143 with doses of 0.1, 0.2 and 0.4 mg./kg. respectively, and orally is 23 and 63.5 with 0.2 and 0.4 mg./kg. respectively.

The process for preparing the compounds of the invention consists in the 'acylation by conventional procedures of 3,8-diaZabicyclo-[3,2,1]-octane of the formula:

CHzCH-CH3 11-1; 14 CHz-(H( 1Hn wherein one of the symbols X and Y is hydrogen and the other represents a hydrogen, an alkyl, aryl, aralkyl, optionally ring-substituted aralkenyl and cycloalkyllo wer-alkyl radical.

The starting compounds are prepared by the process substantially described in our copending application 104,016, filed April 19, 1961, now US. Patent 3,221,015, 'i.e., by hydrogenation of 3,8-diazabicyclo-[3,2,1]octane- 2,4-diones with lithium aluminium hydride in a solvent.

3,281,421 Patented Oct. 25, 1966 Alternatively, individual starting compounds may more advantageously be prepared by other procedures, as will be apparent from the following examples. In any case, such procedures are illustrated in our above named copending applications.

The following non-limitative examples illustrate the invention.

' EXAMPLE 1 3-methyl-8-acetyl-3,8-diazabic'yclo-[3,2,1]-0ctane The starting compound 3-methyl-3,8-diazabicyclo- [3,2,1]-octane is prepared from 3-n1ethyl-8-carbobenzoxy- 3,8-diazabicyclo-[3,2,l]-octane-2,4-dione described in our copending application 104,016, by hydrogenolysis of the carbobenzoxy group and subsequent reduction of the obtained 3-methyl-3,8-diazabicyclo- 3 ,2, l -octane-2,4-dione, as follows:

A mixture of 10 g. of 3-methyl-8-carbobenzoxy-3,8- diazabicyclo-[3,2,1]-octane-2,4-dione, 150 ml. of ethyl alcohol and 4 g. of palladium on charcoal is hydrogenated at atmospheric pressure for 1-2 hours. After filtration of the catalyst and evaporation of the solvent 5.6 g. of 3- methyl- 3,8-diaZabicyclo-[3,2,1] octane-2,4-dione melting at 102-4 C. are obtained.

To 7.5 g. of lithium aluminium hydride in 200 ml. of anhydrous tetrahydrofuran 10 g. of 3-methyl-3,8-diaza- -bicyclo-[3,2,1]-octane-2,4-dione dissolved in 250 ml. of tetrahydrofuran are added. The mixture is refluxed for 5 hours and then stirred for 2 hours at room temperature. After filtration of the hydrates the tetrahydrofuran solution is dried over NagSO, and evaporated to dryness. The residual 9 g. are distilled in vacuo collecting the fraction passing at 84-87 C./30 mm. Hg. There are obtained 5.9 g. of 3-methyl-3,-8-diazabicyclo=[3,2,1]-octane, melting at 239243 C. The corresponding dihydrochloride melts at 300-310 C.

To 8.5 ml. of acetic anhydride 2.9 g. of 3-methyl-3,8- diazabicyclo-[3,2,l]-octane are added portionwise keeping the temperature at 20 C.

The mixture is heated at 60 C. for 1 hour, cooled to room temperature, poured into ice, made alkaline with 50% NaOH and extracted with ether. From the ether solution 4 g. of raw product are obtained and distilled in vacuo collecting the fraction passing at 95 C./ 0.9 mm. Hg. The product solidifies rapidly: yield 2.9 g.; M.P. 40-43 C.

EXAMPLE 2 3-acety l-8-m ethy l-3 ,8-diazabicycl0- [3 ,2,] -0ctane The starting compound 8-methyl-3,S-diazabicyclo- [3,2,11-octane is prepared by hydrogenolysis of 3-benzyl- 8-methyl-3,S-diazabicyclo-[3,2,1]-ootane. This latter is obtained as described in our copending application 104,016, as follows: A mixture of 23 g. of 3-benzyl-8- methyl-3,8-diazabicyclo-[3,2,1]-octane, 6 g. of 10% palladium on charcoal and 400 ml. of absolute ethanol is hydrogenated in an autoclave at 40 C. and 30 atmospheres for 6 hours. Then it is cooled and after filtration of the catalyst the solvent is removed and the residue is distilled in vacuo collecting the fraction at -120 C./40 mm. Hg; yield 12.1 g. of -8-methyl-3,8-diazabicyclo- [3,2,1]-octane boiling at 193-195 C. To 7 ml. of acetic anhydride 2.5 g. of 8-methyl-3,8-diazabicyclo-[3,2,1]-

solvent 3.5 g. of raw product are obtained; 2.6 g. of pure product are obtained by distillation at l07-1l0 C./0.5 mm. Hg. By reacting 2.5 g. of 3-acetyl-8-methyl-3,8- diazabicyclo-[3,2,1]-octane so obtained with 3.2 g. (1.5

moles) of methyl iodide in 150 ml. of ether, 3.2 g. of methiodide are obtained; M.P. 20821l C.

EXAMPLE 3 extracted with ether and dried over N21 SO By evaporation of the solvent 5.6 lg. of oil are obtained, which crystallise on standing. It is recrystallized from ligroin and 4.4 g. of the product melting at 65-68" C. are ob- 3- ti [-8- '0 n l-3,8-diazabi clo- 3,2,1 -0ctane 5 tainedm 2y y Cy 1 EXAMPLE 8 To 2.5 g. of 3-methyl-3,8-diazabicyclo-[3,2,1]-octarle 3-benz0yl-8-methyl-3,8-diazabicyclo-[3,2,1]-0ctane 7 ml. o f prop1oni c acid anhydride are added dropwise To 18 mL of 2 N NaOH 2 of 8 methyJ 38 diaZa Wlth 9 5 keemng the temperature below 30 bicyclo-[3,2,l]-octane are added. The mixture is cooled reaction mixture as then heated for 1 hour at 100 C., 10 and of benzoyl chloride we added dmpwise with cooled, poured into ice, allowed to stand for 10 minutes coolin and Stirrin kee the tem stature at 5 1 0 and made alkaline with 50% NaOH by cooling. An oil g g p p Separ,ateS which then extracted Wlth when The ether The reaction mixture is made alkaline with NaOH, solution, dried over Na SO and Y- p h h water is added to dissolve the precipitate and then it is elves i wh,1ch Pmnfied byodlstlna 15 extracted with ethyl ether. The ether solution is dried tron, collecting-the fraction passing over at 93-98 C./0.4 over Nazso4 and evaporated There are obtained 35 g. of raw product which is purified by distillation col- EXAMPLE 4 lecting the fraction passing over at 158-165 C./ 1 mm. 3-propionyl-8-methyl-3,8-diazabicycl0-[3,2,11-0ctane 122;22 32 Z???gnethyla8 d1aZab1cyc1O- This compound is prepared from 2.5 of S-methyl- EXAMPLE 9 3,8-diazabicyclo-[3,2,1]-octane and 7 ml. of propionic 3-methyl-8-benz0yl-3,8-diazqbicycl0-[3,2,1]-0ctane acld jan'hydnde as f h for the lsomer This compound is prepared substantially as described proplonyl 3,8 dlaozablcyclo octane Yleld for the isomer starting fnom 3-methyl-3,8-diazabicyclo- 112-120 [3,2,1]-octane. It is purified by distillation collecting the fraction passing over at 128l35 C./0.4 mm. Hg, EXAMPLE 5 yield 92%. The corresponding citrate melts at 182- 3-metlzyl-8-butyryl-3,8-diazabicyclo-[3,2,1]-0ctane 184 EXAMPLE 10 To 5 g. of 3-methyl-3,8-diazabicyclo-[3,2,1]-octane 9.1 3-benzyl-8-propionyl-3,8-diazabicycl0-[3,2,1]-0ctane g. of butyric acid anhydride are added dropwise under T 10 of 3-benzyl-3,8-diazabicyclo-[3,2,1]-oetane Stiffihg, keeping the tempehalture below The prepared as described in our copending application h heated at for 2 h Cooled, Poured 104,016, 15 ml. of propionic acid anhydride are added into acldified to 2 8 Ted Wlth eoheehthaied Hcl with cooling and stirring, keeping the temperature at 30 and extracted twlee with The aqueous Phase is C. Then it is heated at 100 C. for 2-3 hours, cooled, made alklahhe W NaOH and extracted Wlth etherpoured into ice, acidified to Congo red and extracted with h dlled Over 2 4 evaporatee ethyl ether, removingthe ether ph ase. The aqueous phase dryness glves Oil Whieh is h Vaeuo glvlhg 40 is made alkaline and extracted with ethyl ether and the 'h a e Ji' ether phase is then dried over Na SO and the solvent E The correspondmg hydrochlonde 1200 is evaporated. The oily residue is rectified in vacuo, collecting the traction passing over at 150-155 C./0.3

EXAMPLE 6 4 mm. Hg; yield 7 g. 3-methyl-8-cinnamoyl-3,8-diazabicyclo-[3,2,1]-0ctane 0 EXAMPLE 11 8-pr0pi0nyl-3,8-diazabicyclo-[3,2,1]-0ctane T0 180 of 2 N NaOH 20 of Y It is prepared according to the preceding example starth -q h are added followed 40 of ing from 3,8-diazabicyclo-[3,2,1]-ootane, described in our P ethyl ether; added dIOP- 5o eopending applications S.N. 86,854 and 104,016. Yield wise under cooling. The mixture is kept stirred at room 82% B P 0 C mm- Hg temperature for 2 hours and extnaoted with ethyl ether. 'EXAMPLES 12 23 The ether solution, dried over Na SO and evaporated to dryness gives 3-methyl-8-cinnamoyl-3,8-d'iazabicyclo- The fellowlhg eompouthds Were P p suhslahhahy [3,2,l]-octane melting at 9294 C. as described in the preceding examples:

3-Substituent S-Substituent 13.1.

i B l 170-5 C./0.6 nn. that that... mi: 586;? 33 'II I QW QVOiQI IiJ II Cinnainyl IIIIIdo 170 0/02 mm.

Do Methyl a-methyltropoyl do (+)-ot-methyltropoyl(monohydrate) d0 ()-a-methy1tropoyl(hydrochloride) d0 Tropoyl do Pllenyl Propionyl Methyl Methyltropoyl (hemihydrate 297.386 98-100 EXAMPLE 7 We claim:

3-methyl-8-pl1enylacetyl-3,8-diazabicyclo- [3,2,11-0ctane To 25.5 ml. of 2 N NaOH 3 g. of 3-methyl-3,8-diazabicyc-lo-[3,2,l]-octane are added, followed by 5.55 g. of phenyl-acetic acid chloride in 5 ml. of anhydrous ethyl ether, added dropwise under cooling and stirring. The mixture is allowed to stand 3 hours at room temperature,

1. 3 (a methyltropoyl) 8 methyl-3,S-diazabicyclo- [3,2,1]-ootane-.

2. 3-- (oz methyltropoyl) 8 methyl-3,8-diazabicyclo-[3,2,1]octane.

3. 3 (a methy-ltropoyl) 8 methyl 3,8 diazabicyclo- 3,2, l -octane.

5 4. 3 methyl 8 pnopionyl 3,8 diazahicyclo-[3,2,l]- octane.

5. 3 cinnamyl 8 propionyl 3,8 diazabicyelto- [3,2,11-0ctane.

6 pp. 2750-2755 (1961), from a thesis submitted by S. W. Blackman to the School of Graduate Study of the Polytechntic Institute of Brooklyn in partial fulfillment of the requirement for the degree of Doctor of Philosophy, June 1960.

ALEX MAZEL, Primary Examiner.

IRVING MARCUS, WALTER A. MODANCE,

NICHOLAS S. RIZZO, Examiners.

N. H. STEPNO, J. W. ADAMS. Assistant Examiners. 

1. 3 - (A : METHYLTROPOYL) - 8 - METHYL-3,8-DIAZABICYCLO(3,2,1)-OCTANE.
 5. 3 - CINNAMYL - 8 - PROPIONYL - 3,8 - DIAZABICYCLO(3,2,1)-OCTANE. 